DOCSLIB.ORG

Bioprocessing Basics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bioprocessing Basics Bioprocessing Basics JUNE 2020 Bioreactors and Fermenters: Powerful Tools for Resolving Cultivation Bottlenecks Ulrike Rasche Advanced Technologies Facilitate Scale-up and Technology Transfer Cynthia Challener A Beginner’s Guide to Bioprocess Modes: Batch, Fed-Batch, and Continuous Fermentation Ying Yang and Ma Sha Sponsored by This custom ebook is sponsored by Eppendorf and presented in partnership with BioPharm International. Bioreactors and Fermenters: Powerful Tools for Bioreactors Scale Up, Fermentation and Fermenters Tech Transfer Resolving Cultivation Bottlenecks SPONSORED CONTENT APPLICATION NOTE Bioreactors and Fermenters: Powerful Tools for Resolving Cultivation Bottlenecks Ulrike Rasche Shake flasks, cell culture dishes, and Introduction T-flasks are the first vessels that come Many applications are well served by the to mind when we think about cultivation cultivation of bacteria or yeast in shake systems for growing eukaryotic and flasks and cells in dishes or T-flasks. prokaryotic cells in the lab. Bioreactors Bioreactors and fermenters, however, improve productivity and save work, and fermenters are another alternative time, and lab space for scientists, who: to consider if we need larger quantities • need large quantities of cells, of cells, increased efficiency of microbes, or the products cultivation, or enhanced reproducibility. they express In this white paper, we explain the key • would like to improve the characteristics of stirred-tank bioreactors reproducibility of growth, the product and which organisms are typically grown formation, or the product quality in them. Using specific examples, • would like to systematically we demonstrate how bioreactors compare different growth conditions and fermenters can help to resolve • would like to increase the cultivation bottlenecks. cultivation efficiency 2 JUNE 2020 | BIOPHARM INTERNATIONAL SPONSORED CONTENT Bioreactors and Fermenters: Powerful Tools for Bioreactors Scale Up, Fermentation and Fermenters Tech Transfer Resolving Cultivation Bottlenecks What are bioreactors Stirred-tank bioreactors and fermenters? Though many types of bioreactors exist, Broadly speaking, bioreactors and we will focus on stirred-tank bioreactors. fermenters are culture systems to The name is accurately descriptive. produce cells or organisms. They Cultivation takes place in the bioreactor are used in various applications, tank—often called a vessel—and the including basic research and culture is mixed by stirring (instead development, and the manufacturing of shaking, for example). Stirred-tank of biopharmaceuticals, food and bioreactors come in different sizes (for food additives, chemicals, and other cultures of a few milliliters to thousands of products. A broad range of cell types liters) and are made of various materials and organisms can be cultivated in (usually glass, plastic or stainless steel). bioreactors and fermenters, including The basic components and functioning cells (like mammalian cell lines, insect of stirred-tank bioreactors are always the cells, and stem cells), microorganisms same. A stirred-tank bioreactor system (like bacteria, yeasts, and fungi), as well consists of several parts (Figure 1): as plant cells and algae. • A vessel that is filled with the Bioreactor and fermenter are two words medium in which cells are cultivated for basically the same thing. Scientists • A head plate to close the vessel who cultivate bacteria, yeast, or fungi often use the term fermenter. The • Components within or attached term bioreactor to the vessel or the head plate to often relates to Figure 1: Stirred-tank bioreactor system consisting of bio- the cultivation process control station, vessel, and bioprocess control soft- of mammalian ware. The BioFlo 120 bioprocess control station is shown cells, but is also generically used. When we talk about bioreactors in this white paper, we usually mean systems for the cultivation of microbes or mammalian cells. 3 JUNE 2020 | BIOPHARM INTERNATIONAL SPONSORED CONTENT Bioreactors and Fermenters: Powerful Tools for Bioreactors Scale Up, Fermentation and Fermenters Tech Transfer Resolving Cultivation Bottlenecks measure and adjust the culturing oxygen is transferred from the surrounding conditions, such as feed lines air to the culture medium. This process and sensors is more efficient in shake flasks than in • A control system comprising static cultures because shaking increases external components used to exposure of the liquid surface. In adjust the culturing conditions (e.g., bioreactors, air or pure oxygen (coming for pumps) and control software example from a compressed air cylinder) is usually introduced to the culture. Creating optimal cultivation conditions With the use of spargers, the gas/liquid Like incubators and shakers, bioreactors interface can be increased and the oxygen allow for the creation of optimal supply maximized. Oxygen is important environmental conditions for the for culture growth, and the amount of growth of cells or microbes. They differ, oxygen dissolved in the medium (dissolved however, in how these are established. oxygen concentration, DO) is continuously Culture mixing. Instead of mixing by measured with a DO sensor. shaking, in a bioreactor, the culture is To keep DO at setpoint, a DO cascade stirred with an impeller. The impeller is is often set up in and executed by the mounted to the impeller shaft, which bioprocess control software. Figure 2 in turn is connected to a motor. In a shows an example for a typical DO bioreactor, not only are bacterial, yeast, cascade. If DO drops below setpoint, first and suspension cell cultures constantly the agitation speed is gradually increased mixed, but so too are the cultures of up to 1,200 rpm to increase oxygen adherent cells attached to a growth matrix. transfer from the surrounding air. If this Tempering. To obtain the right cultivation temperature, a bioreactor does not Figure 2: Dissolved oxygen cascade need to be placed inside a shaker or incubator but can remain on the lab bench. The temperature of the culture medium is continuously monitored with a temperature sensor. To regulate it, the vessel is placed in a thermowell, wrapped with a heating blanket or has a water jacket. Cooling is possible as well. Establishing aerobic or anaerobic conditions. In a shaker or incubator, 4 JUNE 2020 | BIOPHARM INTERNATIONAL SPONSORED CONTENT Bioreactors and Fermenters: Powerful Tools for Bioreactors Scale Up, Fermentation and Fermenters Tech Transfer Resolving Cultivation Bottlenecks is not sufficient to keep DO at setpoint, incubator atmosphere is measured and the gas flow rate is increased up to three controlled, rather than the medium pH. standard liters per minute (SLPM). As a Bioreactors also differ in that a basic final measure, the oxygen concentration solution is often added to compensate in the gas mix is increased, shifting from for acidification during culture growth. gassing with air (containing 21% oxygen) For microbial cultures in bioreactors, toward gassing with pure oxygen. This basic and acid solutions are commonly is just an example. The minimum and used for pH adjustment. This is different maximum values of agitation, gas flow from cultures in shake flasks, where the rate, and oxygen concentration can be culture pH is usually not controlled. optimized depending on the organism Control of parameters at setpoint. In and process needs. bioreactors, different components and Anaerobic conditions can be established by the control software play together to gassing with N2 or other anaerobic gases. control pH, temperature, and dissolved oxygen at the desired setpoint. The pH control. To regulate the pH of parameters are constantly measured carbonate-buffered cell culture media, using pH, temperature, and DO sensors. cell cultures in flasks or dishes are The sensors transmit the information to usually placed in CO incubators. In 2 the bioprocess control software, which bioreactors, the principle is the same; regulates the addition of CO and liquid CO is introduced to the culture from a 2 2 pH agents, the activity of tempering compressed gas cylinder. In bioreactors, devices, agitation, and the gassing with the medium pH is continuously air and/or O2. measured using a pH sensor and CO2 is added as needed. This is different from A typical bioprocess run the situation in a CO incubator, in which 2 To maintain cultures, scientists usually the CO concentration in the internal 2 keep them in cultivation systems within incubators. Bioreactors are usually used Sponsor’s Content for a specific experiment or production run, which may last hours, days, or BioProcessing weeks, depending on the Introduction organism and application. A bioprocess run typically comprises the following steps (Figure 3): 5 JUNE 2020 | BIOPHARM INTERNATIONAL SPONSORED CONTENT Bioreactors and Fermenters: Powerful Tools for Bioreactors Scale Up, Fermentation and Fermenters Tech Transfer Resolving Cultivation Bottlenecks 1. Preculture: The medium in the process parameter setpoints in the bioreactor is inoculated with a bioprocess control software. preculture. Often, the preculture 3. Inoculation: Once the bioreactor is is grown in a shaker or incubator. prepared, the medium is inoculated. Sometimes, smaller bioreactors are 4. Cultivation period: During the used to grow precultures for the cultivation period, agitation, pH, inoculation of larger bioreactors. temperature, and DO are typically 2. Bioreactor preparation: The monitored and controlled in real bioreactor is prepared in parallel
Load more

Recommended publications
  • Microbial Enzymes and Their Applications in Industries and Medicine
    BioMed Research International Microbial Enzymes and Their Applications in Industries and Medicine Guest Editors: Periasamy Anbu, Subash C. B. Gopinath, Arzu Coleri Cihan, and Bidur Prasad Chaulagain Microbial Enzymes and Their Applications in Industries and Medicine BioMed Research International Microbial Enzymes and Their Applications in Industries and Medicine Guest Editors: Periasamy Anbu, Subash C. B. Gopinath, Arzu Coleri Cihan, and Bidur Prasad Chaulagain Copyright © 2013 Hindawi Publishing Corporation. All rights reserved. This is a special issue published in “BioMed Research International.” All articles are open access articles distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Contents Microbial Enzymes and Their Applications in Industries and Medicine,PeriasamyAnbu, Subash C. B. Gopinath, Arzu Coleri Cihan, and Bidur Prasad Chaulagain Volume 2013, Article ID 204014, 2 pages Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611, Mojdeh Dinarvand, Malahat Rezaee, Malihe Masomian, Seyed Davoud Jazayeri, Mohsen Zareian, Sahar Abbasi, and Arbakariya B. Ariff Volume 2013, Article ID 508968, 13 pages A Broader View: Microbial Enzymes and Their Relevance in Industries, Medicine, and Beyond, Neelam Gurung, Sumanta Ray, Sutapa Bose, and Vivek Rai Volume 2013, Article
    [Show full text]
  • Rapid Detection of Bacteria and Viruses in Bioprocess Samples: Justification, Regulation, Requirements and Technologies — How Can Industry Achieve Broad Adoption?
    RAPID DETECTION OF BACTERIA AND VIRUSES IN BIOPROCESS SAMPLES: JUSTIFICATION, REGULATION, REQUIREMENTS AND TECHNOLOGIES — HOW CAN INDUSTRY ACHIEVE BROAD ADOPTION? CONNECT COLLABORATE ACCELERATE TM 1 Contents 1.0 Executive summary .......................................................................................................................................................................... 6 2.0 Introduction ....................................................................................................................................................................................... 8 3.0 Current practices ............................................................................................................................................................................10 3.1 Sterility testing ............................................................................................................................................................................. 10 3.2 Mycoplasma testing .................................................................................................................................................................... 11 3.3 Virus testing .................................................................................................................................................................................. 13 4.0 Drivers for change ...........................................................................................................................................................................15
    [Show full text]
  • Simple Strategies to Improve Bioprocess Pure Culture Processing
    Reprinted from PHARMACEUTICAL ENGINEERING® The Official Magazine of ISPE May/June 2010, Vol. 30 No. 3 Pure Culture Bioprocessing www.ISPE.org ©Copyright ISPE 2010 This article presents Simple Strategies to Improve strategies to improve Bioprocess Pure Culture Processing bioreactions by reducing contaminations by Michael Hines, Chris Holmes, and Ryan Schad by adventitious agents. ioreaction and fermentation processes of traditional bioprocess reactors and fermenta- of all scales – from 100,000 liter vessels tion processes. They are targeted squarely for to small development reactors – require the practitioner in their simplicity, and based pure culture for their successful, pro- on many years of managing pure culture opera- Bductive operation. In this article the term “pure tions at many scales. The focus of this article culture” and “pure culture capability” will be is on preventing bacterial contaminations in used instead of “sterile” or “sterility assurance” traditional fermentation systems; much of the to acknowledge that bioreactions are, by nature, material applies to protection of any bioreactor the process of growing large populations of systems from any adventitious agent. It is up to helpful microorganisms or cells as opposed to you to understand your system and process and the more unwanted varieties. Contamination to appropriately apply the principles outlined in by adventitious agents costs time, money, and order to meet the requirements of your process lost productivity; moreover, contaminants and and business. Higher potential risk from longer their sources can be very difficult to locate and growth times, longer inoculum trains, and lack eliminate. of selective agents (e.g., antibiotics) can be offset Many elements of pure culture bioprocess through the use of disposables, newer equip- design and operation are straightforward, often ment, and more stringent environmental and even a matter of common sense.
    [Show full text]
  • (MBR) Technology for Wastewater Treatment and Reclamation: Membrane Fouling
    membranes Review Membrane Bioreactor (MBR) Technology for Wastewater Treatment and Reclamation: Membrane Fouling Oliver Terna Iorhemen *, Rania Ahmed Hamza and Joo Hwa Tay Department of Civil Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada; [email protected] (R.A.H.); [email protected] (J.H.T.) * Correspondence: [email protected]; Tel.: +1-403-714-7451 Academic Editor: Marco Stoller Received: 14 April 2016; Accepted: 12 June 2016; Published: 15 June 2016 Abstract: The membrane bioreactor (MBR) has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal.
    [Show full text]
  • Biopharma PAT Quality Attributes, Critical Process Parameters & Key
    Biopharma PAT Quality Attributes, Critical Process Parameters & Key Performance Indicators at the Bioreactor May 2018 White Paper: Biopharma PAT Quality Attributes, Critical Process Parameters & Key Performance Indicators at the Bioreactor Table of Contents PAT Building Blocks .................................................................................................... 3 PAT for Biopharma ...................................................................................................... 5 Culture & Fermentation Process Types ....................................................................... 6 Monitoring Methods .................................................................................................... 8 Critical Process Parameters ...................................................................................... 10 Critical Quality Attributes & Key Performance Indicators ........................................... 14 Recent Applications of In-situ VCD & TCD ................................................................ 17 Conclusions .............................................................................................................. 19 References ................................................................................................................ 20 Focus Spots Intelligent Arc Sensors for pH and DO in-situ Measurement...................................... 10 Dissolved Oxygen User’s Experiences ...................................................................... 11 In-situ Cell Density
    [Show full text]
  • Stachytarpheta Cayennensis Aqueous Extract, a New Bioreactor Towards Silver Nanoparticles for Biomedical Applications
    Journal of Biomaterials and Nanobiotechnology, 2019, 10, 102-119 http://www.scirp.org/journal/jbnb ISSN Online: 2158-7043 ISSN Print: 2158-7027 Stachytarpheta cayennensis Aqueous Extract, a New Bioreactor towards Silver Nanoparticles for Biomedical Applications Francois Eya’ane Meva1,2* , Joel Olivier Avom Mbeng1, Cecile Okalla Ebongue1,3, Carsten Schlüsener2, Ülkü Kökҫam-Demir2, Agnes Antoinette Ntoumba4, Phillipe Belle Ebanda Kedi4, Etienne Elanga1, Evrard-Rudy Njike Loudang1, Moise Henri Julien Nko’o1, Edmond Tchoumbi1, Vandi Deli1, Christian Chick Nanga1, Emmanuel Albert Mpondo Mpondo1, Christoph Janiak2 1Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon 2Institute for Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany 3Clinical Biology Laboratory, General Hospital of Douala, Douala, Cameroon 4Department of Animal Biology and Physiology, Faculty of Science, University of Douala, Douala, Cameroon How to cite this paper: Meva, F.E., Abstract Mbeng, J.O.A., Ebongue, C.O., Schlüsener, C., Kökҫam-Demir, Ü., Ntoumba, A.A., Kedi, This study reports the preparation and characterization of silver nanopar- P.B.E., Elanga, E., Loudang, E.-R.N., Nko’o, ticles synthesized by the mediation of the plant weed Stachytarpheta cayen- M.H.J., Tchoumbi, E., Deli, V., Nanga, C.C., nensis through solution method. Ultraviolet visible spectroscopy (UV-Vis) Mpondo, E.A.M. and Janiak, C. (2019) Sta- chytarpheta cayennensis Aqueous Extract, a determines the presence of nanoparticles in the solution. Infrared spectros- New Bioreactor towards Silver Nanopar- copy (IR) proves organic molecules at the particles interface. Powder X-ray ticles for Biomedical Applications. Journal diffraction (PXRD) provides phase composition and crystallinity.
    [Show full text]
  • Bioreactor Studies of Heterologous Protein Production by Recombinant Yeast
    BIOREACTOR STUDIES OF HETEROLOGOUS PROTEIN PRODUCTION BY RECOMBINANT YEAST by ZHIGEN ZWNG A thesis presented to the University of Waterloo in fulNlment of the thesis quinment for the degree of Doctor of Philosophy in Chernical Engineering Waterloo, Ontario, Canada, 1997 @ Zhigen Zhang 1997 National tibrary Bibliothi?que nationale l*l dm, du Canada Acquisitions and Acquisitions et Bibliographie Services seMces bubriographiques 395 wellaStreet 395, me wdtingtori OrtawaON KIAW ûtiawaOlJ K1AûN4 Canada Canada Va#& Voinciilline, avm Nom- The author has pteda non- L'auteur a accordé une licence non exclusive licence dowiug the exclwe permettant il Ia National Ijiiiof Canada to Bibliothèque nationale du Cadade reproduce, 10- disttibute or sell reprodnire, *, distn'buerou copies of bis/her thesis by any means vendre des copies de sa thése de and in any fonn or fomLaf making qyelqy manière et sous quelque this thesis avaiiable to interested forme que ce soit pour mettre des persofls- exemplaires de cette thèse à la disposition des persornes intéressées. The auîhor retains owndpof the L'auteur conserve la propriété du copyright m Merthesis. Neither droit d'auteur qui protège sa thèse. Ni the thesis nor substsmtial extracts la thèse ni &s extmits substantiels de fiom it may be printed or otherwiSe celleci ne doivent être imprimés ou reproduced with the author's autrement reproduits sans son permission. autorisalian, nie University of Waterloo requin% the signatures of ali pesons using or photocopying this thesis. Please sign below. and give address and dite. ABSTRACT Fundamend enginee~gstudies were carried out on heterologous protein production using a recombinant Saccharomyces cerevisiae sPain (C468fpGAC9) which expresses Aspergillus mamon glucoamylase gene and secretes glucoamylase into the extracellular medium, as a model system.
    [Show full text]
  • Optimizing Eukaryotic Cell Hosts for Protein Production Through Systems Biotechnology and Genomescale Modeling
    Biotechnology Biotechnol. J. 2015, 10, 939–949 DOI 10.1002/biot.201400647 Journal www.biotechnology-journal.com Review Optimizing eukaryotic cell hosts for protein production through systems biotechnology and genome-scale modeling Jahir M. Gutierrez1,2 and Nathan E. Lewis2,3 1 Department of Bioengineering, University of California, San Diego, CA, USA 2 Novo Nordisk Foundation Center for Biosustainability, University of California, San Diego School of Medicine, San Diego, CA, USA 3 Department of Pediatrics, University of California, San Diego, CA, USA Eukaryotic cell lines, including Chinese hamster ovary cells, yeast, and insect cells, are invaluable Received 26 FEB 2015 hosts for the production of many recombinant proteins. With the advent of genomic resources, Revised 26 APR 2015 one can now leverage genome-scale computational modeling of cellular pathways to rationally Accepted 03 JUN 2015 engineer eukaryotic host cells. Genome-scale models of metabolism include all known biochemi- cal reactions occurring in a specific cell. By describing these mathematically and using tools such as flux balance analysis, the models can simulate cell physiology and provide targets for cell engi- neering that could lead to enhanced cell viability, titer, and productivity. Here we review examples in which metabolic models in eukaryotic cell cultures have been used to rationally select targets for genetic modification, improve cellular metabolic capabilities, design media supplementation, and interpret high-throughput omics data. As more comprehensive models of metabolism and other cellular processes are developed for eukaryotic cell culture, these will enable further exciting developments in cell line engineering, thus accelerating recombinant protein production and biotechnology in the years to come.
    [Show full text]
  • Raw Materials for Industrial Fermentation Bioprocesses Improvement
    Research Doctorate School in BIOmolecular Sciences Ph.D. in BIOMATERIALS - (2010-2012) RAW MATERIALS FOR INDUSTRIAL FERMENTATION BIOPROCESSES IMPROVEMENT Sergio Pirato Supervisor: Prof. Emo Chiellini Tutor: Dr. Federica Chiellini Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab) - Department of Chemistry & Industrial Chemistry, University of Pisa (Italy). 2 Sergio Pirato – PhD Thesis Sergio Pirato – PhD Thesis 3 Dietro ogni problema c'è un'opportunità. G. Galilei 4 Sergio Pirato – PhD Thesis Foreword: The present doctorate thesis in Biomaterials was formally started at the Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Application (BIOlab), at the University of Pisa, from January to September 2010. After 9 months spent at the BIOlab, the opportunity to continue the PhD as an external candidate at the Novartis Vaccines and Diagnostics came, on a topic of interest for the Biomaterials Doctorate Course. Hence, it was decided also with the consensus of the Tutor & Supervisor to continue the undertaken Doctorate Course as an external candidate without the Institutional Grant originally supplied by the University of Pisa and with the Thesis work plan accepted and endorsed by the Company itself. Therefore the thesis is consisting substantially in two parts: the first minor part is a study aiming at the development of a polymeric product suitable for the formulation of nanoparticle drug delivery systems; the second part, upon the consensus of the Supervisor and Tutor, focused on studies on raw material of biologic origin for the improvement of fermentation bioprocesses. Sergio Pirato – PhD Thesis 5 Table of Content CHAPTER 1 Aim of the Work………………………………………………………………………………. 9 1.
    [Show full text]
  • Guide to Biotechnology 2008
    guide to biotechnology 2008 research & development health bioethics innovate industrial & environmental food & agriculture biodefense Biotechnology Industry Organization 1201 Maryland Avenue, SW imagine Suite 900 Washington, DC 20024 intellectual property 202.962.9200 (phone) 202.488.6301 (fax) bio.org inform bio.org The Guide to Biotechnology is compiled by the Biotechnology Industry Organization (BIO) Editors Roxanna Guilford-Blake Debbie Strickland Contributors BIO Staff table of Contents Biotechnology: A Collection of Technologies 1 Regenerative Medicine ................................................. 36 What Is Biotechnology? .................................................. 1 Vaccines ....................................................................... 37 Cells and Biological Molecules ........................................ 1 Plant-Made Pharmaceuticals ........................................ 37 Therapeutic Development Overview .............................. 38 Biotechnology Industry Facts 2 Market Capitalization, 1994–2006 .................................. 3 Agricultural Production Applications 41 U.S. Biotech Industry Statistics: 1995–2006 ................... 3 Crop Biotechnology ...................................................... 41 U.S. Public Companies by Region, 2006 ........................ 4 Forest Biotechnology .................................................... 44 Total Financing, 1998–2007 (in billions of U.S. dollars) .... 4 Animal Biotechnology ................................................... 45 Biotech
    [Show full text]
  • Improving Citric Acid Production of an Industrial Aspergillus Niger CGMCC
    Xue et al. Microb Cell Fact (2021) 20:168 https://doi.org/10.1186/s12934-021-01659-3 Microbial Cell Factories RESEARCH Open Access Improving citric acid production of an industrial Aspergillus niger CGMCC 10142: identifcation and overexpression of a high-afnity glucose transporter with diferent promoters Xianli Xue1†, Futi Bi1,2†, Boya Liu1,2, Jie Li1, Lan Zhang1, Jian Zhang1, Qiang Gao1 and Depei Wang1,2,3* Abstract Background: Glucose transporters play an important role in the fermentation of citric acid. In this study, a high- afnity glucose transporter (HGT1) was identifed and overexpressed in the industrial strain A. niger CGMCC 10142. HGT1-overexpressing strains using the PglaA and Paox1 promoters were constructed to verify the glucose transporter functions. Result: As hypothesized, the HGT1-overexpressing strains showed higher citric acid production and lower residual sugar contents. The best-performing strain A. niger 20-15 exhibited a reduction of the total sugar content and residual reducing sugars by 16.5 and 44.7%, while the fnal citric acid production was signifcantly increased to 174.1 g/L, representing a 7.3% increase compared to A. niger CGMCC 10142. Measurement of the mRNA expression levels of relevant genes at diferent time-points during the fermentation indicated that in addition to HGT1, citrate synthase and glucokinase were also expressed at higher levels in the overexpression strains. Conclusion: The results indicate that HGT1 overexpression resolved the metabolic bottleneck caused by insufcient sugar transport and thereby improved the sugar utilization rate. This study demonstrates the usefulness of the high- afnity glucose transporter HGT1 for improving the citric acid fermentation process of Aspergillus niger CGMCC 10142.
    [Show full text]
  • A Survey of Selected Topics Relevant to Bioprocess Engineering
    NAT L INST. OF STAND & TECH R.I.C. I nil nil nil II mill nil II mill III III II A111D3 m74Eb United States Department of Commerce Nisr National Institute of Standards and Tectinology NIST PUBLICATIONS NIST Technical Note 1276 A Survey of Selected Topics Relevant to Bloprocess Engineering J. 6. Hubbard, E. J. Clark, and J. M. H. Levelt Sengers QC 100 .U5753 //1276 1990 C.2 NATIONAL msnrUTE OF STANDARDS & TECHNOLOGY Reeearch Informatioii Center GsBtheraburg, MD 20899 DATE DUE Demco, Inc. 38-293 mo NIST Technical Note 1276 A Survey of Selected Topics Relevant to Bioprocess Engineering J. B. Hubbard E. J. Clark J. M. H. Levelt Sengers Thermophysics Division Natic»ial Institute of Standards and Technology Gaithersburg, MD 20899 May 1990 % U.S. Department of Commerce Robert A. Mosbacher, Secretary National Institute of Standards and Technology John W. Lyons, Director National Institute of Standards U.S. Government Printing Office For sale by the Superintendent and Technology Washington: 1 990 of Documents Technical Note 1276 U.S. Government Printing Office Natl. Inst. Stand. Technol. Washington, DC 20402 Tech. Note 1276 88 pages (May 1990) CODEN: NTNOEF ABSTRACT The following is a collection of reports on topics considered important and generic in biotechnology and bioprocess engineering: (1) Isoelectric points of proteins; (2) Solubility and mass transfer of oxygen in bioreactors; (3) Solubility and mass transfer of carbon dioxide in bioreactors. These reports arose from a survey of the past and current biotechnology literature with special effort given to a critique of data measurement quality. The format is as follows.
    [Show full text]